In women's brains, the proportions of white and gray matter are _____ in both hemispheres

According to Piaget, what would be the best way to teach children in kindergarten about the mathematical concept of addition:

a. Explain to them in words how addition problems should be solved and then ask them to explain back to you in their own words. b. Give them objects, such as blocks, to manipulate so they can see how moving blocks from one pile to another represents changes in number (e.g., addition). c. Read stories about math problems to them to enhance their motivation to learn mathematical concepts. d. There is no good way to teach children in the preoperational stage about mathematics because this topic requires the ability to understand reversibility, which develops later.

Morgan has become self-reflective about her thoughts and can now think in terms of abstract principles, such as "democracy" and "honor," as well as making projections regarding the future. Morgan is most likely in which cognitive stage?

a. formal operational b. concrete operational c. preoperational d. preconventional